Firstly, i'm 15 years old. I'm been suffering from mild tinnitus(both ears) for 2 months now. Recently, there is this VERYVERY soft pulsing dubdub-dubdub sound in my ears lasting for a couple of seconds. Is this bad?

I don't listen to loud music. Maybe for a few hours everyday(ever since i got an ipod about a year ago) but i'm sure the volume is pretty good. However, i once accidentally played the ipod at the max volume for about 5 seconds. A day or so after that experience, i started getting the ringing/cricket-ish sound in my ears.

I heard that cochlear damage is only prominent if i listen to loud music for a long periods of probably years. But it's only once for me so i started doubting this as the cause.

I naturally have a crossbite. Not very bad but still, obvious if you look at my teeth. My teeth are perfectly aligned except for my jaw, causing the crossbite.

I also heard that there are some tests to confirm if it is caused by TMJ.
Clenching the teeth - became higher pitched
pressing on forehead and resisting it - became higher pitched
pressing on lower jaw - higher pitched too

I sometime get some wierd neck discomforts that feels like i strained a muscle. Not sure if it's all in my mind or something. Not distinct, very mild. Also, occasionally, some very soft crackling sound when i open my mouth wide,move it side to side,vigorous movements etc. No real pain of any sort though.

So how high are the chances that TMJ is the cause of my tinnitus?
Or what could be the other causes? Sinus etc?
If TMJ is really the cause, please give some info on treatment, cost of treatment etc.
Thank you.